sunken eye

I have a 3 and a half year old boar. Noticed that he is off his food including salad and hay. His eyes are dull and sunken & he is hunched in appearance. He has lost weight too. Poop seems looser. Just doesn't look happy.
Please advise so I can make him comfy.

Hi guys, this is my first ever post and I’m sick with worry about my piggy Scott, chronically ill myself and sleep deprived so please be kind.
Scottie started showing symptoms 3 days ago. Unfortunately we’ve not noticed his weight loss which I really feel bad about. His eyes are small and as...

So about two months ago, someone gave me a guinea pig because he was being mistreated where he lived and after a few days of having him, I noticed his right eye was swollen and sunken so I took him to the vet and he gave me eye drops and told me to use them for a week but it never got better and...